Various types of terminal blocks have been used in the telecommunications industry which provide some means for anchoring an incoming multi-core cable and which have a number of pairs of conductors, known as binding posts, to a base of each of which a conductor of the cable is more or less permanently connected. A top part of each binding post protrudes above an upper surface of the block, and is screw-threaded. A stripped drop wire may be wrapped around the exposed binding post and secured with a washer and nut, thus making a breakable electrical connection between a core of the incoming cable and the drop wire. A terminal block may typically provide for connections to up to 25 pairs of conductors, a pair of conductors of course being required for each telephone.
Several problems may arise with such terminal blocks, in particular corrosion. The binding posts, washer and nuts, and drop wires are liable to corrosion and other environmental damage which results in interference and cross-talk etc. on telephone lines. Provision of a permanent seal around the binding posts or around the whole block is generally not practical since access to the conductors for testing of the lines or for rearrangement of the lines may be required. An excellent re-enterable technique for encapsulation of binding posts is marketed by Raychem under the trademark Termseal, and is disclosed in U.S. Pat. No. 4,634,207, the disclosure of which is incorporated herein by reference. This technique generally requires however, that badly corroded binding posts be properly cleaned and that new washers and nuts be employed before the technique is carried out. That may not always be convenient or possible to ensure.
A further problem is inherent in the design of prior art terminal blocks, in that they require that the drop wires be pre-stripped at their ends before connection to the binding posts. Also, in the case of multi-core drop wires (generally two cores side-by-side, giving the drop wire an oval or almost rectangular cross-section), the drop wire has to be split, i.e. its cores separated for separate connection to spaced-apart binding posts. Thus the wire is split in two, and insulation removed from each of the resulting two wires, and connection then made to the binding posts, after cleaning in the case of repair to an installed block.
The present invention is able to overcome such problems as these by providing an article and a method whereby a non-stripped, non-split, multi-core drop wire can be connected to an existing, prior art terminal block (an exercise that may be referred to as rehabilitation) and preferably to terminal blocks of different binding post separation. The invention also provides a new terminal block whereby such multi-core drop wires may be connected to a multi-core telecommunications cable.